基于重复控制的微电网逆变器控制策略

微电网逆变器有两种工作模式:当电网正常时,微电网逆变器工作于并网模式;当电网发生故障时,微电网逆变器能工作于孤岛模式提供电压支撑。为了微电网逆变器能够在两种工作模式之间平滑切换,提出了针对控制环路切换和相位锁定的优化方法。考虑到微电网逆变器在并网模式下的供能质量会受到电网电压背景谐波的影响。因此,引入了一种与传统重复控制相比具有6倍响应速度的T/6重复控制方法抑制谐波电流。最后通过实验样机验证了所提控制策略的有效性。

Repetitive-control-based Control Technology for Microgrid Inverters

A microgrid inverter has two working modes:when the grid is under normal operation, it can work in a grid-connected mode; and when the grid fails, it can work in an islanding mode to power the local loads continuously. To realize seamless transfer between the two working modes, an optimization method for control loop transition and phase locking is proposed in this paper. In addition, considering that the power supply quality of the microgrid inverter in a grid-connected mode may suffer from the background harmonics in grid voltage, a T/6 repetitive control method is introduced to suppress the harmonic current, which has a six-fold response speed compared with the conventional repetitive control method. Finally, the effectiveness of the proposed strategy was verified through tests on an experimental prototype.